Stenciling machine



Jall- 1961 H. E. WHITTEMORE STENCILING MACHINE Filed Aug. 1, 1957 INVENTOR HAROLD E. WHITTEMORE ATTORNEY STENCILING MACHINE Harold E. Whittemore, East Hempfield Township, Lancaster County, Pa., assignor to Armstrong Cork Company, Lancaster, Pin, a corporation of Pennsylvania Filed Aug. 1, 1957, Ser. No. 675,678

6 Claims. (Cl. 154-23) This invention relates to a stenciling machine for the manufacture of molded inlaid linoleum, inlaid plastic surface coverings, and the like. It is concerned more particularly with a stencil clearing unit for such machines.

In stenciling machine for the manufacture of inlaid surface coverings, a metal stencil is provided, having openings therein through which granulated inlaying compositions are strickled. The stencil openings are generally provided with bridging wires which extend across the stencil openings and are attached to the stencil plate. These wires provide a supporting structure for the solid portions of the stencil disposed between the openings, and they also serve to support the strickling blades in their movement over the stencil. Berger Patent 2,241,051 discloses a stenciling machine of the type referred to, and the wire supported stencil arrangement is shown in Figure 4 of that patent.

In the manufacture of certain inlaid patterns, a background area is provided with openings into which inlays are subsequently deposited. One type of product of this sort is disclosed in Humphreys Patent 2,636,542 wherein the background color is applied through the stencil shown in Figure 3 of that patent. In another type of pattern, large inlays, such as 9" x 9" square areas of granules of different colors, are inlaid to produce a final product in simulation of 9" x 9" cork tiles. In depositing such large areas of granulated inlaying composition through stencil openings, particularly where Wires are required to support the stencil plate, as mentioned above, there is a tendency for the granulated linoleum or similar composition to cling to the stencil wires when the stencil is lifted; and the composition sometimes builds up in these stencil openings resulting in the production of defective material.

The granulated material may be dislodged quite readily if the stencil is struck a sharp blow, preferably near the center of its open area. This induces a shock wave in the stencil which wave travels along the stencil, and adherent particles or agglomerations of adherent particles are parted from the stencil. If this action is imparted to the stencil upon completion of each stenciling operation, there is no tendency for the granulated material to build up in the stencil openings; and thus defective material is not produced.

An object of the invention is to provide a stenciling unit for the manufacture of molded linoleum and similar products with means for dislodging from the stencil adherent granules which may become lodged in the stencil openings, between the stencil wires, or elsewhere.

Another object of the invention is to provide a stenciling unit, as mentioned above, with automatically operated means for dislodging adherent granules upon each cycle of operation of the stenciling unit, without the intervention of a machine operator.

Other objects of the invention will be clear from the following description of an embodiment of the invention att- Patented Jan. 31, 1961 which will be given in conjunction with the attached drawing, in which:

Figure 1 is a side elevation of a strickling unit embodying the invention;

Figure 2 is a view similar to Figure 1 but to a somewhat larger scale showing a part of the stenciling unit and illustrating by solid and by dotted lines the two at rest positions of the shock wave creating mechanism;

Figure 3 is a top plan view of the shock wave creating mechanism and includes part of the framework of the stenciling unit and one of the strickler carriages which has mounted on it an elevating roller for effecting latching of the shock wave creating mechanism; and

Figure 4 is a diagrammatic view showing latching mechanism and indicating schematically the electrical control of a latch-releasing device.

The unit includes a conventional strickler mechanism such as disclosed in the Berger patent referred to above. The metal stencil is indicated at 2; and, as shown in Figure 1, the stencil has openings 3 therein through which granulated linoleum composition or the like is fed onto a supporting backing 4 which is received on a slat type conveyor 5 which is moved intermittently below the stencil 2 to bring fresh areas of the backing 4 into position to receive inlays of linoleum composition or the like to be deposited through the openings 3 in the stencil.

The granulated linoleum composition is received within a hopper 6, and a veined feeder 6" deposits a measured amount of the composition into the path of a plurality of strickling and compressing blades mounted on strickler carriages 7 which are secured to an endless chain carrier. The blades serve when moved over the stencil 2 to distribute the linoleum composition deposited in their path by the veined feeder 6' over the stencil and through the stencil openings 3 onto the backing 4 and to compress the granulated material to a slight degree, as more fully disclosed in the Berger patent.

The stenciling unit is mounted on side rails 8 and 9 which are arranged to be raised upon completion of each stenciling cycle and to be lowered again after. the backing 4 has been moved by conveyor 5 to bring a fresh area into position for the reception of inlaying composition. A table 10 supports the backing i and the slat conveyor 5.

The shock wave creating mechanism shown in the drawing comprises a counterweighted arm 11 which is pivoted at 12 to a bracket 13--14 which is in turn secured to a base plate 15. Base plate 15 is adjustably clamped to a pair of supporting bars 16 and 17 which extend parallel to the length of the strickler unit and are secured to frame members forming part of the unit, as shown in Figure 1.

The arm 11 carries an impacting head 18 which may be made of rubber or other yieldable material. The forward edge of the arm 11 and the head 18 are curved. A counterweight 19 is adjustably received on a rod 2% fixed to the pivoted arm 11. This provides a means for adjusting the force applied by the head falling into engagement with the stencil 2 to create a shock wave of the desired intensity to efiect proper dislodgment of the adherent granules. The shock wave creating mechanism is preferably mounted in such position that the head engages the stencil near the center thereof so that proper and efiicient dislodgment throughout the whole of the stencil will be effected very rapidly. To avoid undue wear on the stencil by repeated impacting of the same by the head 18, the base plate 15 may be periodically shifted on the supporting rods 16 and 17 so that the head engages the stencil at a slightly different position after each adjustment. 7

Movement of the arm 11 from the solid line position shown in Figure 2 to its elevated position as shown in dotted lines in that figure may be eifected conveniently by providing an elevating roller 21 on the first of the strickler blade carriages 7. The roller 21 may be located on the carriage 7 in such position that it will engage the head 18 and, as it moves thereunder, will lift the arm 11 and head 18, the carriage 7 and roller 21 passing thereunder. The roller 21 is mounted on a shaft 22 fjournaled in bearings 23 and 24 secured to angle brackets .25 and 26 attached to the carriage frame, as shown in Figure 3.

A latching mechanism is provided for holding the arm 11 in its upper or cocked position. This is best illustrated in Figures 3 and 4. It includes a supporting bracket 27 mounted on plate 15 by bolts 28 and 29. There is a vertically disposed mounting plate 36 forming part of the bracket 27. Mounted on this plate 30 is a latch guide '31, a latch rod guide 32, and solenoid mounting memhers 33 and 34. A latch 35 is slidable longitudinally in latch guide 31 and has a latch rod 36 secured thereto which extends through latch rod guide 32. A spring 37 encircles rod 36 and lies between guide 32 and the end or" latch 35 to which rod 36 is afiixed. A yoke 38 is secured by a pin 39 to latch 35 and is connected at its opposite end to a movable iron core member 46 of a solenoid 41 mounted between members 33 and 34. Cap screws 42 and 43 pass through slot 44 provided in latch 35 and serve to hold the latch in proper position with respect to latch guide 31 for free movement therealong. The forward end of the latch 35 is inclined as indicated at 4.5 in Figure 4 to facilitate its retraction by a strike and keeper plate 47, and a holding notch 45 is provided in the latch.

The strike and keeper plate 47 is mounted on arm 11 and is provided with a keeper opening 48 therein which receives the notched holding portion 46 of the latch 35 when the arm 11 is elevated to bring the plate 47 into engagement with the inclined portion 45 of the latch 35, causing the latch to be deflected against the action of spring 37 and by reaction of the spring to return the latch to a position where the latch and keeper are in engagement, as shown in Figure 4.

When it is desired to release the arm 11, solenoid 41 is energized which causes member 40 to pull the yoke 38 in the direction of the solenoid, against the action of spring 37, and latch 35 is retracted, withdrawing the same from within the keeper 47. The arm falls by gravity, and the impacting head 18 strikes the stencil a sharp blow near the center of its open working area which induces a shock wave in the stencil which radiates therefrom throughout the extent of the stencil, dislodging adherent particles or granules or agglomerations of them.

The shock Wave is preferably created in the stencil immediately after the stencil has been elevated to a position where it is clear of the inlaying composition which has been deposited through it. This insures that any dislodged particles will fall into proper position on the inlaid areas. This movement of the arm 11 may be controlled precisely by providing an electrical switch 49, the control roller 50 of which is positioned to engage a stationary portion of the machine when the strickling unit is moved to its lowered position, as shown in Figure 2. The control roller is spring-urged to move the switch to a closed position as the stenciling unit is elevated, and the closing of the contacts of the switch may be adjusted to provide for release of the arm 11 at the proper instant when the stencil has been elevated to clear the inlays deposited through the stencil. The switch is preferably arranged to momentarily energize the solenoid to retract the latch 35. The arm 11 is moved to its upper position and latched mechanically by action of the roller 21 carried by the strickler carriage 7 which, as mentioned above, is moved in a closed path over the stencil during each stenciling cycle of the machine. Thus, it will be seen that when the stenciling unit is lowered and the carriages move through their closed path, inlaying composition will be deposited from the hopper 6 by the veined feeder 6' into the path of the strickling members on their carriages 7; and the first carriage will, upon movement under the shock wave inducing device, elevate it to its latched position (as shown in dotted lines in Figure 2) where it will be mechanically held until completion of the stenciling cycle and elevation of the stenciling unit. Thereupon the solenoid 41 will be energized through switch 49 and the latch 35 will be retracted, the arm 11 will fall, bringing the impacting head 18 which it carries into engagement with the stencil plate 2 near its center, and the desired shock wave will be created in the stencil. The head 18 will then rest on the stencil (as shown in solid lines in Figure 2) until the arm is engaged by the roller 21 during the next cycle of operation of the machine.

While it is preferred to use a single impacting head, obviously a plurality of heads may be used to engage different areas of the stencil. For all practical purposes, however, a single unit has been found to operate successfully with stencils 54" wide and 72" long, with both linoleum composition and vinyl type plastic inlaying compositions.

I claim:

1. In a stenciling machine including a stencil plate having openings therein through which granulated inlaying composition may be strickled and means for periodically elevating said stencil plate away from the deposited inlaying composition upon completion of each stenciling operation, the combination of means for creating a shock wave in the stencil plate when said stencil plate is in an elevated position to disengage inlaying composition clinging to said stencil plate comprising an impacting member engageable with the upper surface of said stencil plate, means for holding said impacting member in an elevated position above said stencil plate, and means for releasing said impacting member when said stencil plate is in an elevated position for movement of said impacting member toward said stencil plate to cause said impacting member to strike the upper surface of said stencil plate and create a shock wave therein.

2. In a stenciling machine including a stencil plate having openings therein through which granulated inlaying composition may be strickled and means for periodically elevating said stencil plate away from the deposited inlaying composition upon completion of each stenciling operation, the combination of means for creating a shock Wave in the stencil plate when said stencil plate is in an elevated position to disengage inlaying composition clinging to said stencil plate comprising a pivoted arm, an impacting head carried on the lower end of said arm and engageable with the upper surface of said stencil plate, a latch holding said arm in an elevated position with said head disposed above said stencil plate, and means responsive upon movement of said stencil plate to an elevated position for releasing said arm for movement toward said stencil plate to cause said impacting head to strike the upper surface of said stencil plate and create a shock wave therein.

3. In a stenciling machine including a stencil plate having openings therein through which granulated inlaying composition may be strickled and means for periodica-lly elevating said stencil plate away from the deposited inlaying composition upon completion of each stenciling operation, the combination of means for creating a shock wave in the stencil plate when said stencil plate is in an elevated position to disengage inlaying composition clinging to said stencil plate comprising a pivoted arm, an impacting head carried on the lower end of said arm and engageable with the upper surface of said stencil plate, a latch holding said arm in an elevated position with said head disposed above said stencil plate, electrical means for releasing said latch, and a switch responsive 'upon movement of said stencil plate to an elevated position for controlling said electrical means to release said arm for swinging movement toward said stencil plate to cause said impacting head to strike the upper surface of said stencil plate and create a shock wave therein.

4. In a stenciling machine including a stencil plate having openings therein through which granulated inlaying composition may be strickled, strickler carriages movable over said stencil plate in a closed path to strickle granulated inlaying composition through said stencil openings, and means for periodically elevating said stencil plate away from said deposited inlaying composition upon completion of each stenciling operation, the combination of means for creating a shock wave in the stencil plate when said stencil plate is in an elevated position to disengage inlaying composition clinging to said stencil plate comprising a pivoted arm, an impacting head carried on the lower end of said arm and engageable with the upper surface of said stencil plate, a latch for holding said arm in an elevated position with said head disposed above said stencil plate, means carried by one of said carriages for bringing said arm into latching relationship with said latch with said arm in said elevated position, and means responsive upon movement of said stencil plate to an elevated position for releasing said arm for pivotal movement toward said stencil plate to cause said impacting head to strike the upper surface of said stencil plate and create a shock wave therein.

5. In a stenciling machine including a stencil plate having openings therein through which granulated inlaying composition may be strickled, strickler carriages movable over said stencil plate in a closed path to strickle granulated inlaying composition through said stencil openings, and means for periodically elevating said stencil plate away from the deposited inlaying composition, the combination of means for creating a shock wave in the stencil plate when said stencil plate is in an elevated position to disengage inlaying composition clinging to the stencil plate comprising a pivoted arm, an impacting head mounted on said arm and engageable with the upper surface of said stencil plate, a latch mounted in fixed position, a striker plate and keeper carried by said arm and engageable with said latch to hold said arm in an elevated position, a solenoid for retracting said latch, a switch for controlling the 6 supply of current to said solenoid for actuation of the same, and means for actuating said switch upon movement of said stencil plate to an elevated position above said inlaid composition to release said arm for movement toward said stencil plate to cause said impacting head to strike the upper surface of said stencil plate and create a shock wave therein.

6. In a stenciling machine including a stencil plate having openings therein through which granulated inlaying composition may be strickled, a plurality of strickler carriages movable over said stencil plate in a closed path to strickle granulated inlaying composition through said stencil openings, a framework supporting said strickler carriages for movement, means for periodically elevating said stencil and said framework with the carriages supported thereby to an elevated position with said stencil plate removed from the deposited inlaying composition strickled therethrough, the combination of means for creating a shock wave in the stencil plate when said stencil plate is in an elevated position to disengage inlaying composition clinging to said stencil plate comprising a mounting plate adjustably secured to said strickler framework, an arm carrying an impacting head engageable with the upper surface of said stencil plate, means for pivoting said arm to said mounting plate, a latch carried by said mounting plate for holding said arm in an elevated position with said head disposed above said stencil plate, and means responsive upon movement of said stencil plate to an elevated position for retracting said latch to release said arm from said latch for movement of said arm toward said stencil plate to cause said impacting head to strike the upper surface of said stencil plate and create a shock wave therein.

References Cited in the file of this patent UNITED STATES PATENTS 

